Best available cop



(No Model.)

BEST-AvAxL/ALE COP 'Patented-rbflg, 1889.

sEsrAvAiLAeLECoP UNITED STATES PATENT GEEICE.-

EDlVARD T. BIRDSALL, l? NElV YGRII, N. Y.

sTATic-IN-DUCTION e ENE RAToR.

SPECIFICATION formngpart of Letters Patent No. 398,122, dated February19, 1889 Application filed November 14, 18S-8. Serial No. 290,786. (NomodelJ To all whom t may concern:

Be it known that I, EDWARD T. BIRDSALL, of the city and State of ANewYork, have invented an Improvement in Electric Induction and InuenceMachines, of Which the follow-A ing is a specification. Y

Electric induction and influence machines have heretofore been made inwhich two disks of glass have been revolved in 'opposite directions, andupon the surfaces of-the glass there have been strips of foil, and thestatic charge induced has been received upon combs, and there have beenconductors connectedwith the combs through which the current has.

been transmitted to any instrument or apparatus-such, for instance, -asGeissler tubes f A or other appliances for demonstrating electriceffects.

My present invention relates to the details of construction of suchmachine, whereby -I am enabled to simplify the same, lessen the cost,and render the apparatus more efficient.

It is to be understood that this apparatus is especially adapted for theuse of students, schools, and colleges, and it is' available fordemonstrating electrical operations in which static electricity is madeuse of.

In the drawings,Figure l is an elevation of the apparatus. Fig. 2 is avertical section through the axis of the disks. Fig. 3 is a horizontalplan, partially in section, of the combs; and Fig. l is an elevation ofthe central portion of one of the disks, showing the mode of fasteningthe saine to the hub.

The base A is usually quadrangular, having cross-pieces 2 at the endsand standards B at the sides supporting the shaft C, and also an axis,D. At one end ofthe shaft C is a crank-handle, E, and upon the shaft Cbetween Jthe standards B there are two beltwheels, F and G, with belts3, topulleys 4 5 upon the respective hubs H and I. These hubs H and Iare preferably of wood and tubular, and through them the axis D passes,such axis being` formed of a strong wire. The

'glass disks K and L are each formed with the central opening, 6,notched at its edges for the reception of the screw 7, and therespective hubs II I are fitted into the central openings of therespective disks, and the screws 7 pass into the hubs through thenotches in the glass for securing the disks to the inner der t0 preventmoisture condensing upon "such disks and interfering with thedevelopment of the electric current, and there are strips of foilsecured to the outer faces of the respective disks, which stripsusually-occupy radial positions, as represented in Fig. l. One of thebelts 3 is. .crossed and the other is straight, so that by rotating theshaft C by the handle E the hubs H and I and the respective glass disksconnected with them are revolved rapidly and in opposite directions.

.The brushes N are made of line wire or preferably of bunches of tinsel,and these are vsupported by the diagonal arms O, which arms are of sheetmetal, and each end of each arm is made with a lateral projection, 8,that is folded around to inclose the base of the bunch of wires orbunches of tinsel, and these are securedby solder run into a loop formedby the folded lateral projection 8. These arms O are received intosaw-cuts in the standards B and are held by the axis D,passing through ahole in each arm, and the bases of the sawcuts in the standards are atabout an angle of forty-five degrees to the horizon, so that therespective arms and brushes stand diagonally and in opposite directionswith the brushes against the faces ofthe respective disks. I find thisis a cheap, coiwenient, and efficient mode of constructing the brushes,

, and it allows for replacing the brush es cheaply and rapidly, shouldthey become injured.

Upon the end base pieces, 2, are the columns P, which are made of woodand hollow for the reception of the glass rods Q, and at the upper endsof these glass rods Q are the knobs R, forming the bases of the combs S,and each knob R has a cylindrical connection, l0, around the upper endof the glass rod. I find in practice that these knobs, combs, andcylinders can be cast in one, of pewter or similar soft metal, aroundthe upper ends of the glass rods, and they remain firmly connectedthereupon, especially whore the glass rod is slightly indented with afile or otherwise at.

one side to prevent the knob turning thereon, and through each knob ahole is cored or l formed by a pin introducedinto the mold and IOOafterward driven out of the casting, through which hole the wire Tpasses, and each wire T is L-shaped or bent at a right angle andterminates with the knob or electrode U. The 5 wires T are to fit theholes inv the knobs RY tightly, so that there will be sufficientfriction to allow forswinging the wires and knobs nearer together orfarther apart, as indicated by the dotted lines in Fig. 1, so as 'tolengthen or shorten the are between the electrodes.

In practice thiselectric'machine is very efiicient, and it occupies butasmall space, and for transportation the parts can be separated withfacility and packed into a small space, and there is but little difcultyin taking the machine apart or putting it together, because the Wires Tcan be pulled out from the knobsV R and readily inserted, and byVwithdrawing" remox'f'ed from position and packed, so aste preventinjury to such glass disks in transe .the arms o can ais be nffed' mafain the standards and packedA separately.

r siam my invenaon nshed surfaces and provided with strips ofV ing, in'combination with the Wood'e' hubs H I, tting into the central openingsthe respective disks and securedb'fy'scrvvs, aiidthe removable axis D,standards `B, and' Abase substantially asset forth. v 4. 3 5 2.,TheknobsR, combs S, and cylinders 10,'

the axis-D the hubs and glass disks can be portatiomand ivhn the axis Dis r'iv'ed 1. The glass disks K and L, having foil and each having acentral notched pel'i'v eEsT AVAMBLE cciD Y B, and the arms O andbrushes N, the stand- .ards being slotted or saw-cut diagonally for thereception of the'ams, and the arms being perforated for thepassage ofthe axis, substantially as set'feitli` .s 4i The veombinatim in ,theelectric in'a chine, f-tlie glass disksls L, Wooden hubsH I, tov'vl'i'hl the glasfsfdisks; are connected, the base A and standards"B,;th removable' @fris D, passing ,through the and taidads', the shaftG, belt-vili "ls-Fv G', and belts to pnlT ley iii res' ilvfhbs, thearins'fO slots itli', standards', t e" o' ft'l,V @dds f the arifi's, the@the glass, rods Q, faire wiesr, passing g` nios", and t ele i-odes atthe ends of h wires, rally asset forth.

Signed by ine this 8th day of November, 65

